ESTRO 2023 - Abstract Book

S1092

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ESTRO 2023

cases by multidisciplinary teams. Experts were asked to score each statement on a 5-point Likert scale. The agreement was scored to be either absent/poor (<50%), fair (50%-75%), or consensus ( ≥ 75%). Results A total of 48 experts participated in the starting meeting, both Delphi rounds, and the consensus meeting (overall response rate: 71%). OMD was considered in patients with metastatic esophagogastric cancer limited to 1 organ with ≤ 3 metastases or 1 extra-regional lymph node station (consensus). In addition, OMD was considered in patients without progression at restaging after systemic therapy (consensus). For patients with synchronous or metachronous OMD with a disease-free interval ≤ 2 years, systemic therapy followed by restaging to consider local treatment was considered as treatment (consensus). For metachronous OMD with a disease-free interval >2 years, either upfront local treatment or systemic treatment followed by restaging was considered as treatment (fair agreement).

Conclusion The OMEC project has resulted in a multidisciplinary European consensus statement for the definition, diagnosis, and treatment of oligometastatic esophagogastric cancer. This can be used to standardize inclusion criteria for future clinical trials.

PO-1363 Comparison of different Biological Effective Doses in SBRT for hepatic metastases

E. Jimenez-Jimenez 1 , M. Martí 2 , J.M. Nieto-Guerrero 2 , P. Redondo 2 , M.E. Perez 3

1 Hospital General Universitario de Ciudad Real, Radiation Oncology Department, Ciudad real, Spain; 2 Hospital General Universitario de Ciudad Real, Radiation Oncology Department, Ciudad Real, Spain; 3 Hospital General Universitario de Ciudad Real, Physics department , Ciudad Real, Spain Purpose or Objective Stereotactic Body Radiation Therapy (SBRT) is a treatment option for patients with liver metastases. This study evaluated the impact of different Biological Effective Doses using an α / β of 10 Gy (BED10Gy) in SBRT of hepatic metastases. Materials and Methods This is a single-center retrospective study of patients with liver metastases treated with SBRT. Patients were divided into two groups: ≤ 100 Gy and >100 Gy BED10Gy The main outcomes were local control (LC) and overall survival (OS). LC was assessed by hepatic computed tomography. Cox regression analyses were performed to determine prognostic variables on LC and OS.

Results